基于变压器套管升高座处电流互感器的高频局部放电监测技术  

High-frequency Partial Discharge Monitoring Technology Based on TAs in Transformer Bushing Risers

作　　者：郝震 江长明[3] 李欢 成德良 唐云鹏 刘光伟 牛铮 穆卡 HAO Zhen;JIANG Changming;LI Huan;CHENG Deliang;TANG Yunpeng;LIU Guangwei;NIU Zheng;MU Ka(State Grid Jibei Electric Power Research Institute,Beijing 100045,China;North China Electric Power Research Institute Co.,Ltd.,Beijing 100045,China;Northwest Branch of State Grid Corporation of China,Xi’an 710048,China;North China Bratch of State Grid Coporation of China,Beijing 100053,China;State Grid Jibei Electric Power Co.,Ltd.,Beijing 100054,China)

机构地区：[1]国网冀北电力有限公司电力科学研究院,北京100045 [2]华北电力科学研究院有限责任公司,北京100045 [3]国家电网公司西北分部,西安710048 [4]国家电网公司华北分部,北京100053 [5]国网冀北电力有限公司,北京100054

出　　处：《高电压技术》2025年第3期1126-1134,共9页High Voltage Engineering

摘　　要：局部放电(简称局放)监测对变压器安全稳定运行至关重要,研究一种可用于离线和在线的非侵入式局放监测手段可以大幅提升变压器运行安全性。使用升高座模型探究了套管升高座处电流互感器(套管TA,工程上亦称为套管CT)感知高频信号的机理,验证了基于套管TA监测变压器内部局放这一方案的可行性。对1台500k V变压器上安装的11个套管TA进行了传输阻抗、波形畸变率及线性度等参数的测试,验证了套管TA符合标准要求,能够作为高频电流传感器使用。在1台500 kV真型变压器击穿试验中,使用套管TA连接检测设备进行了局放采集试验,结果显示其能有效采集到高频放电信号,与套管末屏、铁芯夹件接地等处测得的信号趋势一致并线性相关,相关系数大于0.91,在本次试验中,信噪比高于铁芯接地HFCT 3.86倍,高于末屏接地HFCT 2.60倍,验证了基于套管TA监测变压器内部局放的可行性与准确性。Partial discharge monitoring is crucial for the safe and stable operation of power transformers.The develop-ment of non-invasive monitoring methods applicable to both offline and online scenarios can significantly enhance operational safety.We investigated the mechanism of high-frequency signal detection by current transformers(bushing TAs,also referred to as bushing CTs in engineering practice)installed in bushing risers through modeling,and verified the feasibility of internal transformer partial discharge monitoring by using bushing TAs.Tests were conducted on 11 bushing TAs installed on a 500 kV transformer to evaluate parameters such as transfer impedance,waveform distortion rate,and linearity.Results confirmed that the bushing TAs met relevant standards and could function effectively as high-frequency current sensors.During breakdown tests on a full-scale 500 kV transformer,partial discharge signals were successfully captured by using bushing TA-connected detection equipment.The acquired signals demonstrated consistent trends and strong linear correlation(correlation coefficient>0.91)with measurements from bushing taps and core clamp grounding points.Notably,the signal-to-noise ratio of bushing TA measurements exceeded that of core-grounding HFCT by 3.86 times and surpassed bushing-tap HFCT by 2.60 times.These findings validate both the feasibility and accuracy of imple-menting bushing TA-based monitoring for internal transformer partial discharges.

关 键 词：变压器 工频电流互感器 电流互感器 高频电流 局放监测 在线监测 

分 类 号：TM452[电气工程—电器]